1. Field of the Invention:
The present invention relates to the field of portable hoists and carrying devices, and particularly to a combination unit.
2. Description of the Prior Art:
A variety of devices have been provided in the prior art for lifting and transporting cargo. Many of these devices have included a lower platform supported on wheels, a vertical support structure, and a boom having a cable hoist associated therewith. Some of these devices, however, have fairly complicated structures which make them relatively cumbersome and expensive, and not readily collapsed for storage.
In U.S. Pat. No. 4,190,233 issued to Godfrey on Feb. 26, 1980, there is described a jack of this general type. The Godfrey jack includes a frame supported on wheels and having an elaborate vertical support mounted thereto. The vertical support includes a first, primary post mounted to the horizontal frame with multiple braces. A second vertical post is also mounted to the frame, and is secured at the top end to the first post. A boom is attached to the top end of the first post, and a brace is slidably supported on the second post and supports the boom. A jack is mounted to the frame on the end opposite the primary post, and a motorized winch is mounted to the top end of the first post and includes a cable extending along the boom and over a pulley thereon.
A portable crane is described in U.S. Pat. No. 1,380,779 issued to Craig on June 7, 1921. The crane includes a lower frame comprising a pair of horizontally extending legs secured together at one end and being supported by wheels at both the secured and the free ends. A vertical post extends upwardly from a cross-member connecting the legs intermediate their ends. A boom extends at an upward angle from the middle of the post, and is supported by a pair of rods extending from the free end of the boom to the top end of the post. A winch is secured to the lower end of braces connecting between the support legs and the vertical post, and a chain extends from the winch over a pulley mounted to the top end of the post and over a second pulley mounted at the free end of the boom.
A portable hoist is described in U.S. Pat. No. 2,634,875 issued to Trautner on Apr. 14, 1953, which includes a horizontal bottom frame mounted on wheels, and carrying a pair of telescoping posts extending upwardly therefrom. A winch is mounted to the lower, outer post secured with the frame, and includes a cable which connects with the lower end of the inner telescoping post to be operable to raise and lower the inner post relative the outer post.
A stationary hoisting apparatus is described in U.S. Pat. No. 1,021,585 issued to Ewert on Mar. 26, 1912. The Ewert device includes a post secured in the ground and having a boom pivotally mounted to its upper end and supported by a cross brace extending between the post and the boom. A winch is mounted on the lower half of the vertical post and includes a cable which runs to a pulley secured to the free end of the boom.
A variety of winch assemblies are known in the prior art. Examples of such devices are shown in U.S. Pat. Nos. 3,603,171 issued to Dodge on Sept. 7, 1971; 4,008,881 issued to Ross on Feb. 22, 1977; 4,199,133 issued to Gagnon, et al. on Apr. 22, 1980; and 4,531,715 issued to Weins on July 30, 1985.